Genetics and Other Risk Factors for Past Concussions in Active-Duty Soldiers.

Risk factors for concussion in active-duty military service members are poorly understood. The present study examined the association between self-reported concussion history and genetics (apolipoprotein E [APOE], brain-derived neurotrophic factor [BDNF], and D2 dopamine receptor genes [DRD2]), trait personality measures (impulsive-sensation seeking and trait aggression-hostility), and current alcohol use. The sample included 458 soldiers who were preparing to deploy for Operation Iraqi Freedom/Operation Enduring Freedom. For those with the BDNF Met/Met genotype, 57.9% (11/19) had a history of one or more prior concussions, compared with 35.6% (154/432) of those with other BDNF genotypes (p = 0.049, odds ratio [OR] = 2.48). APOE and DRD2 genotypes were not associated with risk for past concussions. Those with the BDNF Met/Met genotype also reported greater aggression and hostility personality characteristics. When combined in a predictive model, prior military deployments, being male, and having the BDNF Met/Met genotype were independently associated with increased lifetime history of concussions in active-duty soldiers. Replication in larger independent samples is necessary to have more confidence in both the positive and negative genetic associations reported in this study.

Brain-derived neurotropic factor polymorphisms, traumatic stress, mild traumatic brain injury, and combat exposure contribute to postdeployment traumatic stress.

BACKGROUND: In addition to experiencing traumatic events while deployed in a combat environment, there are other factors that contribute to the development of posttraumatic stress disorder (PTSD) in military service members. This study explored the contribution of genetics, childhood environment, prior trauma, psychological, cognitive, and deployment factors to the development of traumatic stress following deployment. METHODS: Both pre- and postdeployment data on 231 of 458 soldiers were analyzed. Postdeployment assessments occurred within 30 days from returning stateside and included a battery of psychological health, medical history, and demographic questionnaires; neurocognitive tests; and blood serum for the D2 dopamine receptor (DRD2), apolipoprotein E (APOE), and brain-derived neurotropic factor (BDNF) genes. RESULTS: Soldiers who screened positive for traumatic stress at postdeployment had significantly higher scores in depression (d = 1.91), anxiety (d = 1.61), poor sleep quality (d = 0.92), postconcussion symptoms (d = 2.21), alcohol use (d = 0.63), traumatic life events (d = 0.42), and combat exposure (d = 0.91). BDNF Val66 Met genotype was significantly associated with risk for sustaining a mild traumatic brain injury (mTBI) and screening positive for traumatic stress. Predeployment traumatic stress, greater combat exposure and sustaining an mTBI while deployed, and the BDNF Met/Met genotype accounted for 22% of the variance of postdeployment PTSD scores (R (2)  = 0.22, P < 0.001). However, predeployment traumatic stress, alone, accounted for 17% of the postdeployment PTSD scores. CONCLUSION: These findings suggest predeployment traumatic stress, genetic, and environmental factors have unique contributions to the development of combat-related traumatic stress in military service members.

Amelioration of experimental autoimmune encephalomyelitis by anatabine.

Anatabine, a naturally occurring alkaloid, is becoming a commonly used human food supplement, taken for its claimed anti-inflammatory properties although this has not yet been reported in human clinical trials. We have previously shown that anatabine does display certain anti-inflammatory properties and readily crosses the blood-brain barrier suggesting it could represent an important compound for mitigating neuro-inflammatory conditions. The present study was designed to determine whether anatabine had beneficial effects on the development of experimental autoimmune encephalomyelitis (EAE) in mice and to precisely determine its underlying mechanism of action in this mouse model of multiple sclerosis (MS). We found that orally administered anatabine markedly suppressed neurological deficits associated with EAE. Analyses of cytokine production in the periphery of the animals revealed that anatabine significantly reduced Th1 and Th17 cytokines known to contribute to the development of EAE. Anatabine appears to significantly suppress STAT3 and p65 NFκB phosphorylation in the spleen and the brain of EAE mice. These two transcription factors regulate a large array of inflammatory genes including cytokines suggesting a mechanism by which anatabine antagonizes pro-inflammatory cytokine production. Additionally, we found that anatabine alleviated the infiltration of macrophages/microglia and astrogliosis and significantly prevented demyelination in the spinal cord of EAE mice. Altogether our data suggest that anatabine may be effective in the treatment of MS and should be piloted in clinical trials.

Apolipoprotein E genotype-specific short-term cognitive benefits of treatment with the antihypertensive nilvadipine in Alzheimer's patients--an open-label trial.

BACKGROUND: Evidence suggests that dihydropyridine calcium channel blockers may be useful in preventing and treating Alzheimer's disease (AD). OBJECTIVE: In an open-label trial of safety and tolerability of nilvadipine in patients with AD, we examined cognition and executive function over a short time period to determine an influence of nilvadipine on these outcomes. METHOD: We investigated change in cognition using the Mini mental state examination and in executive function using the EXIT25 in 55 patients with AD who received nilvadipine 8 mg daily for 6 weeks compared with 30 non-treated subjects with AD. Apolipoprotein E genotyping was performed, and the study team and caregivers were kept blinded to APOE ε4 status during the trial. RESULTS: Aside from differences in gender and education, both the treatment and the control groups were similar in general demographics and on baseline cognition status. After correction for potential confounders, APOE ε4 status, and use of other antihypertensive medications, a significant impact of study intervention was observed on MMSE (F = 8.67, p < 0.01) and EXIT (F = 8.77, p < 0.03) scores. An interaction between APOE ε4 carrier status and treatment (p ≤ 0.05) was observed for both outcome measures. CONCLUSION: In this open-label trial, among APOE ε4 non-carriers, we observed stabilization of cognition and improvement in executive function among treated individuals compared with non-treated individuals. Among APOE ε4 carriers, cognitive stabilization was evident for treated individuals whereas a cognitive decline was observed in non-treated individuals. These findings provide additional evidence for potential therapeutic efficacy of nilvadipine in treating AD and warrant further investigation.

Anatabine lowers Alzheimer's Aß production in vitro and in vivo.

Brain Aß accumulation represents a key pathological hallmark in Alzheimer's disease. In this study, we investigated the impact of anatabine, a minor alkaloid present in plants of the Solanacea family on Aß production in vitro using a cell line overexpressing the human amyloid precursor protein (APP) and in vivo using a transgenic mouse model of Alzheimer's disease. In vitro, anatabine lowers Aß1₋40 and Aß1₋42 levels in a dose dependent manner and reduces sAPPß production without impacting sAPPα levels suggesting that anatabine lowers Aß production by mainly impacting the ß-cleavage of APP. Additionally, we show that anatabine lowers NFκB activation at doses that inhibit Aß production in vitro. Since NFκB is known to regulate BACE-1 expression (the rate limiting enzyme responsible for Aß production), we determined the impact of anatabine on BACE-1 transcription. We show that anatabine inhibits BACE-1 transcription and reduces BACE-1 protein levels in human neuronal like SHSY-5Y cells suggesting that the Aß lowering properties of anatabine are mediated via a regulation of BACE-1 expression. In vivo, we show that an acute treatment with anatabine for four days significantly lowers brain soluble Aß1₋40 and Aß1₋42 levels in a transgenic mouse model of Alzheimer's disease. Altogether our data suggest that anatabine may represent an interesting compound for regulating brain Aß accumulation.

Flavonoids lower Alzheimer's Aß production via an NFκB dependent mechanism.

Alzheimer's disease (AD) is characterized by the brain accumulation of Aß peptides and by the presence of neurofibrillary tangles. Aß is believed to play an important role in AD and it has been shown that certain flavonoids can affect Aß production. Recently, it was suggested that the Aß lowering properties of flavonoids are mediated by a direct inhibition the ß-secretase (BACE-1) activity, the rate limiting enzyme responsible for the production of Aß peptides. Westernblots and ELISAs were employed to monitor the impact of flavonoids on amyloid precursor protein processing and Aß production. A cell free chemoluminescent assay using human recombinant BACE-1 was used to assess the effect of flavonoids on BACE-1 activity. The effect of flavonoids on NFκB activation was determined by using a stable NFκB luciferase reporter cell line. Molecular docking simulations were performed to predict the binding of flavonoids to the BACE-1 catalytic site. Real time quantitative PCR was used to determine the effect of flavonoids on BACE-1 transcription. We show in a cell free assay that flavonoids are only weak inhibitors of BACE-1 activity. Docking simulation studies with different BACE-1 structures also suggest that flavonoids are poor BACE-1 inhibitors as they appear to adopt various docking poses in the active site pocket and have weak docking scores that differ as a function of the BACE-1 structures studied. Moreover, a weak correlation was observed between the effect of flavonoids on Aß production in vitro and their ability to lower BACE-1 activity suggesting that the Aß lowering properties of flavonoids in whole cells are not mediated via direct inhibition of BACE-1 activity. We found however a strong correlation between the inhibition of NFκB activation by flavonoids and their Aß lowering properties suggesting that flavonoids inhibit Aß production in whole cells via NFκB related mechanisms. As NFκB has been shown to regulate BACE-1 expression, we show that NFκB lowering flavonoids inhibit BACE-1 transcription in human neuronal SH-SY5Y cells. Altogether, our data suggest that flavonoids inhibit Aß and sAPPß production by regulating BACE-1 expression and not by directly inhibiting BACE-1 activity.

HIV-1 envelope accessible surface and polarity: clade, blood, and brain.

UNLABELLED: The human immunodeficiency virus type-1 (HIV-1) gp160 (gp120-gp41 complex) trimer envelope (ENV) protein is a potential vaccine candidate for HIV/AIDS. HIV-1 vaccine development has been problematic and charge polarity as well as sequence variation across clades may relate to the difficulties. Further obstacles are caused by sequence variation between blood and brain-derived sequences, since the brain is a separate compartment for HIV-1 infection. We utilize a threedimensional residue measure of solvent exposure, accessible surface area (ASA), which shows that major segments of gp120 and gp41 known structures are solvent exposed across clades. We demonstrate a large percent sequence polarity for solvent exposed residues in gp120 and gp41. The range of sequence polarity varies across clades, blood, and brain from different geographical locations. Regression analysis shows that blood and brain gp120 and gp41 percent sequence polarity range correlate with mean Shannon entropy. These results point to the use of protein modifications to enhance HIV-1 ENV vaccines across multiple clades, blood, and brain. It should be noted that we do not address the issue of protein glycosylation here; however, this is an important issue for vaccine design and development. ABBREVIATIONS: HIV-1 - human immunodeficiency virus type 1, AIDS - acquired immunodeficiency syndrome, ENV - envelope, gp160 - 160,000d glycoprotein, gp120 - 120,000d glycoprotein, gp41 - 41,000d glycoprotein, LANL - Los Alamos National Laboratories, PDB - Protein Data Bank, HVTN - STEP HIV vaccine trial, AA - amino acids, MSA - multiple sequence alignment, ASA - accessible surface area, SNPs- single nucleotide polymorphisms, HAART - Highly Active Antiretroviral Therapy, CCR5 - C-C chemokine receptor type 5, CNS - central nervous system, HIVE - HIV encephalitis, P - polarity, NP - non-polarity, CTL - cytotoxic T lymphocyte, NIAID - National Institute of Allergy and Infectious Diseases.

Improving image analysis in 2DGE-based redox proteomics by labeling protein carbonyl with fluorescent hydroxylamine.

Recent advances in redox proteomics have provided significant insight into the role of oxidative modifications in cellular signalling and metabolism. At present, these techniques rely heavily on Western blots to visualize the oxidative modification and corresponding two dimensional (2D) gels for detection of total protein levels, resulting in the duplication of efforts. A major limitation associated with this methodology includes problematic matching up of gels and blots due to the differences in processing and/or image acquisition. In this study, we present a new method which allows detection of protein oxidation and total protein on the same gel to improve matching in image analysis. Furthermore, the digested protein spots are compatible with standard MALDI mass spectrometry protein identification. The methodology highlighted here may be useful in facilitating the development of biomarkers, assessing potential therapeutic targets and elucidating new mechanisms of redox signalling in redox-related conditions.